I'm tired of sharing negative things only, so here's maybe something positive:
I've been on bugfix spree with KDE Plasma 6.5 beta. Found bunch of bugs in folderview, which is the thing that shows desktop icons and file icons inside folder widget. They should be more robust now, though I'm still hammering on an annoying edgecase crash.
I have also spent some time to make the widgets less laggy when they're moved on the desktop.
And uh a lot more i forget.
What's interesting though is that most bugs are related to very specific edge cases, I rarely see bugs that are in the way of normal use.
Edit: remember its a collective effort and im just one guy heh. I'm thankful to my employer i can do this as my dayjob :) But most people are volunteers and anyone can join! https://community.kde.org/Get_Involved